Electric flat-iron.



H. P. BALL.

ELECTRIC FLAT IRON.

APPLICATION FILED Aue.6. 1909.

Patented Aug. 10, 1915 2 SHEETS-SHEET l.

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Inventof: Henry F. BalL n m WM H. P. BALL.

ELECTRIC FLAT AAAAAAAAAAAAAAAAAAAAAAAA 9. 1 149, 1 72. Patented Aug. 10, 1915.

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Witnesses Inventor:

M Hem g P. Ball, W

STATES PATENT OFFICE. i

HENRY PRICE BALL, 0F PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC FLAT-IRON.

Specification of Letters Patent.

Patented Aug. 10, 1915.

Application filed August 6, 1909. Serial No. 511,521.

transformed into heat in a reliable, simple.

and efficient manner.

.The principal object of my invention is to produce an electric heater in which the heating unit is arranged so as to be in intimate thermal relation with the body to be heated.

More specifically, my invention relates to electric flat irons, my object being to produce a flat iron in which the resistance unit is cast in the body of the flat-iron in a thoroughly efficient manner.

In carrying out myinvention, I'form a resistance unit in the form of a flat strip and cast the same on edge in the body of the flat iron. The unit is cast in the body in a plane perpendicular to the line of greatest contraction during the cooling of the cast iron, thereby tightly gripping the unit and forming an excellent oint between the metal tional view of the iron; Fig. 2 represents a.

plan view of the bottom portion of the iron; Fig. 3 represents a perspective view of the heating unit; Fig. 4 represents a fragmentary view of the body portion of the iron with the unit cast in a modified form; Figs. 5, 6 and 7 are modifiedforms of castin unit; Fig. 8 represents a-modified form of the resistance conductor; Fig. 9 represents a further modification of my inventlon; and Fig. 10 represents a section view of the same.

Referring to the drawings, 10 represents the body portion having a heating unit 11 cast therein. This unit is formed of a flat strip and is cast on edge, that is, it stands in the body of the iron in a plane perpendicular to the plane of the iron and also in a plane perpendicular to the plane of greatest contraction in cooling. The unit is preferably looped or reflexed, as shown in Fig. 2, to enable as much of the unit as possible to run transversely to the longitudinal length of the iron,-as I find the iron shrinks greater lengthwise than crosswise,

and this subjects the sides of' the unit to enormous pressure, when the cast iron bears down upon it. The reflexing also prevents any tendency on'the part of the sides of the flattened tube to open up due to mechanical strain. It also looks the mica or other insulation inside the tube so that it cannot shift. The unit itself consists of a zigzag resistance conductor 12, which may be formed in any desired manner, as for in stance, by punching it'out of sheet metal. The material out of which this is formed is preferably of high resistance and nonoXidizable. I have found that the resistance metal disclosed in the patent to Dempster, Patent No. 901,428, is very suitable for this purpose. The resistance conductor is zigzagged so as to form a strip, and is laid between two strips of insulating material 13, such for instance, as mica, and insulating members 14, which may also be of mica,

are secured between the sections of the conductor, as shown in Fig. 3. These insulating members are placed at intervals along the conductor to prevent the conductor from contacting with the inclosing casing. The resistance conductor with its mica strips is then inclosed in a flat tube, as shown in Fig. 3. The tube is flattened to the form necessary, and may then be further flattened so as to compress the members tightly.

In Fig. 4-1 have shown the unit arranged in a slightly modified form. In this case the unit is looped back and forth from the toe of the iron so as to make it hotter at. the point or toe of the iron'thanelse- In Fig. 7 I have shown a modified form of unit in which the casing, instead of being in the form of a tube, is in the form of a U- shaped casing 17, which opens outward. By this construction, the gases which are formed during the casting-in process are allowed to escape.

In Fig. 8 I have shown another method of forming the unit, which consists in slotting a strip of mica l8 and Winding a strip of resistance 19 in the slot.

In Figs. 9 and 10 I have shown a flattened tube, as in Figs. 1 and 2, with the upper edge exposed, but differing from that shown in Figs. 1 and 2. This edge is notched, exposing the inner part of the tube to the air. This allows a ready escape, both for the air and gases, into the cope, during the process of casting the iron about the unit, and this enables me to use an insulating material, in which a hydrocarbon binder is used or where sheets of mica are held together with such material, as shellac or paraifin, which carbonize and vent as carbon dioxid through these notches.

While I have described my invention as embodied in concrete form for purposes of illustration, it should be understood that I do not limit my inventionthereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States, 1s,

1. An-electric flat iron comprising a body portion having a Hat heating unit cast therein transversely to the plane of the body and bent back and forth in said plane.

2. An electric flat iron comprising a body portion having a flat heating unit formed from a zigzag resistance conductor cast therein transversely to the plane of the body and bent back and forth in said plane.

3. An electric fiat iron comprising a body portion having a flat heating unit reflexed and cast into the body.

4. An electric flat iron comprising a body portion having a resistance unit inclosed in a flattened tube reflexed and cast transversely to the plane of the body.

5. An electric flat iron comprising a body portion having a resistance unit cast there in, said unit comprising a fiat resistance conductor between insulating strips inclosed in a flattened tube.

6. An electric flat iron comprising a body portion having a resistance unit cast therein, said unit comprising a fiat resistance conductor between strips of insulating material provided with insulating members for preventing endwise movement and inclosed in a flattened tube.

7. An electric fiat iron comprising a body portion having a resistance unit cast therein, said unit comprising a fiat zigzag resistance conductor between strips of insulating material, insulating members secured between the sections of said conductor to prevent endwise movement, and a flattened tube inclosing the same.

In witness whereof, I have hereunto set. my hand this 29th day of July, 1909.

. HENRY PRICE BALL.

Witnesses:

J. O. MUsoRovE, JAMES S. SMYSER. 

